To answer your question re: BTUs.
I have looked into the rated/claimed BTUs on both traditional and all-electric systems and find that neither one reports realistic/plausible numbers.
It is like going to walmart and buying a 5HP hand vacuum. There is a test that they will point at that outputs that value, but it is meaningless and deceptive.
I have intentionally not posted the BTU numbers from either because I do not believe them.
You can get good BTU numbers for household systems because there is a legally mandated methodology for it. If such a mandate/standard test exists for automotive systems, I have not seen it.
